The invention relates to a surgical apparatus for testing nerves.
In high-frequency surgery (“HF surgery”), tissue structures are cut or coagulated by means of surgical instruments attached to surgical devices. If such tissue structures have nerves running through them, using such a surgical instrument can damage or destroy those nerves. If, for example, nerves in the face are damaged, the facial expressiveness of the patient can be impaired.
For this reason, it is common practice that when cutting or coagulating tissue that may has nerves running through it, a surgeon will apply a test current at the cutting or coagulation site to effect stimulation of the relevant muscle. From this test, it can be determined if a muscle region will be affected by the cut and a decision can then be made to make the cut elsewhere. However, to perform a test in this manner, a direct current or low-frequency alternating current must be available. This is usually provided via separate nerve testing equipment.
U.S. Patent Application Publication No. 2006/0184164 A1 discloses an HF surgery device with a surgical instrument that can be operated in cutting, coagulating, and stimulating modes. The device comprises a direct current supply which provides a test current for stimulating nerves, and an HF generator which provides high-frequency current for cutting or coagulating tissue. However, this HF surgical apparatus has a complex design and occupies a large amount of space.
WO 00/13600 discloses an HF surgical device with a high-frequency current instrument for treating motor nerves. As well as treating nerves, stimulation of nerves is possible and both functions can be carried out with the same device. The energy for treating the tissue is provided by an HF generator, whereas the energy for stimulating the tissue is provided by a pulse generator. However, the HF surgical instrument disclosed by WO 00/13600 is also relatively complex and bulky.